What do an empty lot and the wasteland underneath an overpass have in common? They're both unused space.

The wide range of unused space in the city got the people at MSA Architects thinking about the Five Design Challenge. Their offices on Fourth Street overlook a lot that has been empty for too long. Instead of putting the space to good use, the owner put up a fence. That fence sparked ideas. Why not find other unused spaces around the city and see what people, designers, architects, artists, would do with the it?

"Michael Schuster [Founder of MSA] wanted to start a dialogue about general design issues and opportunities in Cincinnati," says Chris Rohs, project designer at MSA. "He's a very community-minded person."

The competition evolved from an earlier idea last year. Last year, competitors were charged to convert drivers to riders -- to come up with a solution to get drivers off the road and using public transportation. Almost 40 entrants offered ideas, but that doesn't begin to compare to this year's level of interest.

The competition is to take one of the five downtown spaces, come up with an idea for it and submit it. The options are as varied as entrants' imaginations: create a destination, a park, a zoo, an art gallery, something temporary, something permanent, something temporarily permanent.

Submissions will be accepted until April 26; winners will be chosen by May 15; $5,500 in prizes will be handed out. Jurists include Tamara Harkavy of ArtWorks, Chad Munitz of 3CDC, Leah Spurrier of High Street, William Williams of DAAP and City Council member Wendell Young.

Five Design Challenge is meant to be all-encompassing and include as many entrants, from as many professions as possible. So far, Nick Dewald, who handles the entries as they come in, has seen entrants from Italy, China, Australia, India, Germany and around the US. Currently, there are more entrants from outside Cincinnati than from within.

"The whole idea is to get people to be more active in their community," Rohs says. "To work to make it a better place."